Ok, so having sorted the other thousand and one problems with this bike (1995 VFR 750) I have stumbled across another I need a bit of light shining on! I took the bike for a test ride round the black before going off to my MOT but as I accelarated up through the gears I noticed I was still doing 5mph and I know I was not really travelling at that speed. I have had the bike to bits again for the 3rd day running (3rd mot slot missed!!!) and have deduced the following: Plastic coupler is in good condition, Good continuity at the back of the speedo gauge the speedo sensor is putting out a reading of about 0.017 Vs DC at maximum when rotated Is this likey to be the speed sensor at fault? Secondly are the VFR 800fi sensors the same? as there are a few on ebay but none that will fit my 1995 straight off.
I'm shocked! This issue is almost always the darn coupler. Have you tried spinning the sensor with a cordless while observing the reading on the speedo? I don't have the diagram for the 95 model but looking at the 98 there is a 10A fuse that could be suspect which powers the Br/Bu wire. The P wire sends the signal to the ECM (which you won't have) and the speedo. If it isn't a power issue, the coupling is good and all else looks fine, I would suspect the sensor. When you have a DMM hooked up to it and spin it does the voltage increase or? It may not increase as the system will be looking for pulses not voltage. You can't test this with the DMM.
I have spun the sensor with a cordless but nothing happens to the speedo gauge at all its just down at 5mph the whole time When I spun the sensor it had a fluctuating voltage but it was extremely minimal as mentioned around 0.017v max, i read in the vfr 800 manual that the reading should be between 0-12v fluctuations i dont know about the 95model though Thanks for the info btw
